JPH08149363A - Shake reduction device, optical device and camera - Google Patents

Abstract

PURPOSE: To reduce the initializing time and to eliminate the need for the adjustment or a correction means to correct a DC offset by eliminating the need for a capacitor for cutting off a DC component in the shake reduction device for a device operated while a person holds the device by hand so as to attain advantages of cost and mount capacity. CONSTITUTION: The device is provided with a detection means 11 that detects a state of the device and provides an output of the detection state as an analog signal, an amplifier 12 amplifying an output of the detection means 11 by a prescribed gain, an A/D converter means 13 converting an output of the amplifier means 12 into a digital signal, a signal processing means 13 changing 1st and 2nd values in response to an output of the A/D converter means 13, and a correction means 17 operated depending on the 1st value of the signal processing means 151 and also with a D/A converter means 14 converting the 2nd digital value into an analog signal and limiting the operating point of the amplifier means 12 by using the analog signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus operated by a human being while holding it by hand, for example, a photographing apparatus such as a still camera or a movie camera, an observation apparatus such as a scope, and a laser rod used for a presentation. The present invention relates to a blur reduction device such as a lighting device such as a flashlight or a flashlight, an optical device, and a camera.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a conventional blur reduction device applied to a video movie camera, for example. Figure 5
In the figure, 11 is a detection means for detecting the state of a hand-held operating device (not shown) such as an optical device and a camera, for example, using a gyro to detect the angular velocity of the behavior of the device. The DC signal component of the angular velocity signal, which is the output of the gyro, is first cut by the low-pass cut filter composed of the capacitor C21 and the resistor R21, and is added to the positive input of the amplifier (operational amplifier) 12 (the resistor R22 and the resistor R23.
It is amplified with a predetermined gain (set by).

The amplified output of the gyro is converted into a digital value by the A / D conversion circuit 13 and thereafter digitally processed.

First, the output of the A / D conversion circuit 13 is added to the integration circuit 22 of the next stage via the low-pass cut filter means 21 having a variable cutoff frequency. The integrating circuit 22 converts the limited angular velocity signal into an angle signal. The amplitude of one of the outputs of the integration circuit 22 is evaluated by the sequence processing means 23, and the cutoff frequency of the low-pass cut filter means 21 is appropriately controlled. The other output of the integration circuit 22 is transmitted to the image cutout control circuit 25 through the interface 24, the cutout position of the captured image is determined, and the blurring is reduced. Further, the sequence processing means 23 uses the analog switch SW in the initialization processing such as when the power is turned on.
2 is closed and a process of setting the electric charge of the capacitor C21 to a steady state is performed.

FIG. 6 is a block diagram showing another conventional apparatus,
This is a blur reduction device applied to movie cameras.

In FIG. 6, an operational amplifier 12 and a resistor R3 are provided.
1, R32 form an inverting amplifier circuit 51. Further, the operational amplifier 30, the resistor R33, and the capacitor C31 form an integrating circuit 52, and the average D of the outputs of the above inverting amplifier circuit 51.
Operational amplifier 12 with C voltage as reference voltage (ground in the figure)
And the field back circuit by 30 has the function of stabilizing. The angular velocity signal, which is the output of the gyro that detects the angular velocity of the behavior of the device, is output from the amplifier 12 (resistor R31
(Set by the same R32) is amplified with a predetermined gain.

In the integrating circuit 31, the angular velocity signal input via the amplifier 12 is converted into an angle signal. The output of the integrating circuit 31 is input to the correcting means 17 and is also added to the limiting circuit 32 constituted by the absolute value circuit 32-1 and the function circuit 32-2, and the characteristic of the limiting circuit 32 is controlled. .

When the analog switch SW3 is turned on in response to the output of the limiting circuit 32, the resistors R34 and R35 and the capacitor C32 have no effect and the characteristic of the primary HPF is obtained. On the other hand, when the analog switch SW3 is turned off, the effects of the resistors R34 and R35 and the capacitor C32 are added, and the characteristics are less likely to be saturated even with panning.
Therefore, the frequency characteristic can be continuously changed by driving the switching of the analog switch SW3 with the rectangular signal whose duty is continuously changed, which is the output of the limiting circuit 32.

The difference circuit 17a in the correction means 17 is
Descriptions of operations of the drive circuit 17b and the variable apex angle prism 17c are omitted.

[0010]

Since the conventional vibration reduction device is constructed as described above, it is necessary to use a large capacity capacitor for the purpose of cutting the DC component, etc., although there are some differences, which is costly. It was also a disadvantage in terms of mounting volume. Further, in terms of electrical characteristics, there is a problem that some kind of correction means or filter means for correcting the leakage current of the capacitor, which cannot be ignored, is required.

An object of the first to eighth inventions of the application is to solve the above-mentioned conventional problems, and an object thereof is to obtain an image stabilization device which does not require a capacitor. To do.

A second object of the present invention is to obtain an optical device equipped with the shake reduction device of the first aspect.

A third object of the present invention is to obtain a camera provided with the shake reduction device of the above-mentioned claim 1.

[0014]

In order to achieve the above object, a first aspect of the present invention relates to a detecting means for detecting the state of a device and outputting the detected state as an analog signal, and the detecting means. Means for amplifying the output of the amplifier with a predetermined gain, and A for converting the output of the amplifier means into a digital signal.
It has an A / D conversion means, a signal processing means whose first and second values change according to the output of the A / D conversion means, and a means which operates according to the first value of the signal processing means. In the device, since the second value, which is a digital signal, is converted into an analog signal, and the D / A conversion means for controlling the operating point of the amplification means according to the converted analog signal is provided, the analog section is provided. This is to realize a low-cost shake reduction device with stable performance and minimum digital processing without a capacitor.

Further, the output of the detection means is amplified by a DC-coupling amplifier circuit, and the operating point of the DC-coupling amplifier circuit is set in accordance with the output signal so that the output signal of the amplifier circuit has an amplitude around a reference potential. It has a system for feedback control, and A / D conversion and D
Since the digital processing system including the A / A conversion is used, the large-capacity capacitor can be eliminated.

A second invention relating to the present application is to obtain an optical device equipped with a shake reduction device having the operation and effect of the first invention.

A third invention according to the present application is to obtain a camera equipped with a shake reduction device having the operation and effect of the first invention.

[0018]

【Example】

First Embodiment FIG. 1 is a configuration diagram of an image stabilization apparatus that best represents the features of the present invention. In FIG. 1, a detection means for detecting the angular velocity of the behavior of an optical device (not shown) and a handheld operating device such as a camera. The angular velocity signal output from the gyro 11 is
In the amplifier 12, it is amplified by the amplifying means 120 having a predetermined gain set by the resistors R11 and R12. The amplified angular velocity signal is immediately converted into a digital value V1 by the A / D conversion circuit 13, and this digital value V1 is used for three digital processes thereafter.

The amplifying means 120 comprises an operational amplifier 12 and two resistors R11 and R12, one of the resistors R11 having one end at the output end of the detecting means 11 and the resistor R11.
The other end of the resistor R12 and the other end of the resistor R12 are at the negative input end of the operational amplifier 12, and the other end of the other resistor R12 and the input end of the A / D conversion means 13 are at the output end of the operational amplifier 12, and D / The output terminal of the A conversion means 14 is connected to the positive input terminal of the operational amplifier 12, respectively.

First, the first destination of the digital value V1 is the integrating means 151, and the angular velocity signal is integrated here and converted into an angle signal. Since the integrator 151 has a characteristic of being attenuated with a predetermined time constant, it is accurately a low-pass filter having a considerably low cutoff frequency. The output V2 of the integrating means 151 is D /
It is converted into an analog signal by the A conversion circuit 16 and transmitted to the correction means 17 by the optical system to optically correct the blur. The output V2 is also applied to the limiting circuit 32 constituted by the absolute value circuit 152-1 and the function circuit 152-2 and converted into the gain setting value (KK). The gain setting value KK controls the variable gain amplifying circuit 153 to change the amplification factor between 0 and 1 times the digital value V1. The limiting means 152 takes the absolute value of the output V2 and selects a gain setting value from the minimum to the maximum by a predetermined function.

The second destination of the digital V1 is the variable gain amplifying means 153, which is the variable gain amplifying means 15.
The output of 3 is multiplied by a constant gain K5 and added to the high pass filter 155 to obtain the output V4. The third destination of the digital value V1 is the predetermined gain amplifying circuit 154, which is multiplied by K_FIL to become the output V5. This output V5 is added to the above-mentioned output V4 and integrated by the integrating means 156. .

The output value (V7) of the integrating means 16 is D /
The signal is again converted into an analog signal by the A conversion circuit 14,
Applied to the positive input of amplifier circuit 12.

Next, the processing functions from A / D conversion to D / A conversion will be described.

An amplifier circuit composed of the operational amplifier circuit 12 and resistors R11 and R12, a predetermined gain amplifier circuit 154,
The integrating means 156 forms a first-order low-pass filter. As a result, the gyro output, which is indeterminate in terms of direct current, changes around a predetermined potential and is added to the A / D conversion as a signal that has undergone the necessary amplification.

In addition, at the time when system initialization is required, such as when the power is turned on, the predetermined gain amplification circuit 154 is required for the required time.
It is possible to quickly set the system to a stable state by setting the predetermined gain of 1 to a large value and operating the system.

When the device greatly changes the angle, such as during panning, when the output V2 of the integrating means 151 tends to deviate from the center, the limiting means 152 detects this and the gain of the variable gain amplifying means 153 is increased. Change to one direction.

Second Embodiment The processing portion for the above A / D conversion to D / A conversion which operates as described above may be constituted by a hardware logic circuit or may be realized by a computer. The following is an example of a program when implemented by a computer.

The description language is C, and only the digital processing portion is extracted and described using the variables corresponding to the respective values shown in FIG.

The constants are examples when the sampling frequency is about 500 Hz, and the gyro sensitivity is about 1 mV / deg.
/ Sec, the amplifier gain is about 45 times, the optical correction amount of the correction system is about 1 deg / V, and the unit of each variable is Vo.
It is lt.

{#Define GAIN 0.07 #define K_FIL -0.0003 #define K3 0.995 #define K_INT 0.9999 #define K5 -0.002 float V1, V2, V3, V4, V5, V6, V7: float KK; float z [4]; V2 = V1 * GAIN + z [3] * K_INT; KK = V2; if (KK <0.0) KK = -KK; // absolute value KK = -0.75 + (KK * 2.5); if (KK <0.0) KK = 0.0; if (KK <1.0) KK = 1.0; // Function V3 = V1 * KK * K5; V4 = V3-z [2] + z [1] * 3; V5 = V1 * K_FIL; V6 = V4 + V5; V7 = V5 + z [0]; z [0] = V6; z [1] = V4; z [2] = V3; z [3] = V2;} Initialization is a constant K_FIL when the power is turned on. Can be realized by setting a larger absolute value and repeating a predetermined number of times, and ON / OFF of driving can be realized by switching the constant GAIN to zero.

The above operation will be described with reference to the flowchart shown in FIG. The system shown here starts its operation when the power is turned on (501). Initialization of the entire system including hardware is performed in a loop of processing from 502 to 506. First, in 502, constants are set so that each variable easily converges. In 503, calculation from A / D input to D / A output of D / A conversion circuit 16 is performed. In 504, A / D is performed.
Calculation from input to D / A output of D / A conversion circuit 14,
At 505, the delay element is updated.

The constant K_FIL is set to an absolute value larger than a normal value, and the feedback loop including the analog amplifier 12 quickly converges to a stable state. Here, the number of loops is set to 100, and the stable state is reached in about 0.2 seconds.

When the initial setting is completed, the constants in the normal operation state are set at 507, and the normal 500 Hz sampling infinite loop is entered. First, at 508, ON / OFF of the anti-vibration switch is checked, and when ON, GA
Set IN to the appropriate value and zero when OFF. 5
Reference numeral 09 denotes an A / D input to D / A input to D / A conversion circuit 1
6 is a calculation process up to D / A output.

Reference numeral 510 is a process for taking the absolute value of the integrated output value,
Reference numeral 511 denotes a polygonal line function process, and the conversion shown in FIG. 3 is performed by the processes 510 and 511. The gain setting value KK obtained here indicates the strength of the panning control. 512 is A
/ D input to D / A input to D / A of D / A conversion circuit 14
The gain setting value KK obtained above is involved in the arithmetic processing up to the A output. At 513, the delay element is updated.

The above is the processing of one sampling,
The process waits until the next sampling process starts.

According to the present system, since an extremely simple program as described above can be realized including the panning processing, an inexpensive microcomputer is sufficient, and the A for other purposes can be installed in the same device. / D conversion and D
A / A conversion, microcomputer, etc. (for example, in a video camera, etc., a high-performance microcomputer for autofocusing, multi-input A / for various purposes)
If it is a D converter or a multi-output D / A converter), all 100
Since it is not necessarily used, the control unit of the blurring reduction system can be configured with almost no increase in cost by utilizing these surplus portions.

Third Embodiment FIG. 4 shows various structural examples of the amplifying means 120. FIG. 4A shows an operational amplifier 12 and two resistors R41.
1 and R412, one end of the resistor R412 is used as an output end of the D / A conversion means 14 and the other end of the resistor R411 is used as a negative input end of the operational amplifier 12, and The other end of the resistor 411 and the input end of the A / D conversion means 13 are connected to the output end of the operational amplifier 12, and the output end of the detection means 11 is connected to the positive input end of the operational amplifier 12.

FIG. 4B is composed of an operational amplifier 12 and three resistors R421, R422 and R423, and the resistor R
One end of 421 is the output end of the detection means 11 and the other end of the resistance is another resistance R422, R423 is the negative input end of the operational amplifier 12, the other end of the other resistance R422 and the A / D conversion means 13 To the output terminal of the operational amplifier 12, the resistor R
The other end of 423 is connected to the output end of the D / A conversion means 14, and the positive input end of the operational amplifier 12 is connected to a predetermined potential.

FIG. 4C is composed of an operational amplifier 12 and four resistors R431 to R434. One end of the resistor R431 is set to a predetermined potential and the other end of the resistor R432 and one end of the resistor R432 are connected to the operational amplifier 12. At the negative input end, the other end of the resistor R432 and the input end of the A / D conversion means 13 are used as the output end of the operational amplifier 12, and one end of the resistor R433 is used as the output end of the detection means 11.
The other end of the resistor and one end of the resistor R434 are connected to the positive input end of the operational amplifier 12, and the other end of the resistor R434 is connected to the output end of the D / A conversion means 14.

[0040]

As described above, the first aspect of the present application
According to the invention, the following unique effects can be obtained. (1) All the large-capacity capacitors required for cutting the DC component and realizing the long time constant can be eliminated, which is advantageous in terms of cost and mounting volume. (2) By digitally processing all time constant control,
The time required for initialization when the power was turned on was greatly reduced. (3) Since the large amplitude input is already limited at the input stage of the A / D converter, the dynamic range of A / D conversion or the number of effective pits can be saved. (4) Since no capacitor is required, there is no leakage current to the capacitor. Therefore, no adjustment or correction means for correcting the DC offset caused by the offset voltage of the operational amplifier is required.

According to the second invention of the present application, there is an effect that it is possible to obtain an optical device equipped with the shake reduction device having the operation and effect of the first invention.

According to the third invention of the present application, there is an effect that it is possible to obtain a camera equipped with the shake reduction device having the operation and effect of the first invention.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a blur reduction device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a processing operation of a blur reduction device according to a second embodiment of the present invention.

FIG. 3 is a function characteristic diagram showing the strength of panning processing.

FIG. 4 is a configuration diagram of an amplification means according to a third embodiment of the present invention.

FIG. 5 is a block diagram of a conventional blur reduction device.

FIG. 6 is a block diagram of a conventional blur reduction device.

[Explanation of symbols]

 Reference Signs List 11 gyro (detection means) 12 operational amplifier (amplification means) 13 A / D conversion circuit 14, 16 D / A conversion circuit 17 correction means 151 integration means (signal processing means) 153 variable gain amplification means 154 predetermined gain amplification means 22, 151, 156 integrating means

Claims (10)

[Claims] 1. A detection means for detecting the state of the device and outputting the detection state as an analog signal, an amplification means for amplifying the output of the detection means with a predetermined gain, and an output of the amplification means converted to a digital signal. A / D conversion means for
An apparatus having a signal processing unit whose first and second values change according to the output of the D / D conversion unit, and a unit operating according to the first value of the signal processing unit, wherein the device is a digital signal. An image stabilization device comprising a D / A conversion means for converting the second value into an analog signal and controlling the operating point of the amplification means by the converted analog signal. 2. The device is an optical device, the device state is at least one of position and orientation (angle), and the detection means is at least one of a velocity sensor, an acceleration sensor, an angular velocity sensor, and an angular acceleration sensor. The means for operating are means for changing the apex angle of the prism, means for shifting the lens in the direction perpendicular to the optical axis, means for rotating the lens around an axis orthogonal to the optical axis, and optical means for the image pickup device. Means for shifting in the direction perpendicular to the axis, means for changing the reflection angle of the mirror,
2. The blur reduction device according to claim 1, wherein the blur reduction device is at least one of means for electronically changing a cutout area of an image pickup screen. 3. The signal processing means integrates an output value of the A / D conversion means and attenuates with a predetermined time constant, and an output value (V2) of the first integration means. Gain changes according to the output value (V1) of the A / D conversion means.
A variable gain amplifying means having an input, a predetermined gain amplifying means having an output value of the A / D converting means as an input, and a value (V that changes according to the output value (V3) of the variable gain amplifying means.
4) and a second integrating means for adding and integrating the output value (V5) of the predetermined gain amplifying means, the second value depending on the output value (V7) of the second integrating means. The blurring reduction device according to claim 1, wherein the blurring reduction device changes. 4. The output value (V3) of the variable gain amplifying means.
4. The vibration reduction device according to claim 3, wherein the frequency characteristic of the value (V4) that changes according to is that the low-frequency gain is lower than the high-frequency gain. 5. The amplifying means has one end of a first resistor as an output end of the detecting means, and the other end of the first resistor and one end of a second resistor as a negative input end of an operational amplifier. The other end of the second resistor and the input end of the A / D conversion means are connected to the output end of the operational amplifier, and the output end of the D / A conversion means is connected to the positive input end of the operational amplifier. The shake reduction device according to claim 1. 6. The amplifying means connects one end of the first resistor to D.
The other end of the first resistor and the second end are connected to the output end of the / A conversion means.
One end of the resistor is the negative input end of the operational amplifier, the other end of the second resistor and the input end of the A / D conversion means are the output end of the operational amplifier, and the output end of the detection means is the positive end of the operational amplifier. The vibration reduction device according to claim 1, wherein the vibration reduction device is configured to be connected to the input end. 7. The amplifying means has one end of the first resistor as an output end of the detecting means, the other end of the first resistor and a second end,
One end of the third resistor is connected to the negative input end of the operational amplifier and the second
The other end of the resistor and the input end of the A / D conversion means to the output end of the operational amplifier, the other end of the third resistor to the output end of the D / A conversion means, and the positive input end of the operational amplifier. The vibration reduction device according to claim 1, wherein the vibration reduction device is configured to be connected to a predetermined potential. 8. The amplifying means has one end of a first resistor at a predetermined potential, the other end of the first resistor and one end of a second resistor as a negative input end of an operational amplifier, and the second resistor. And the other end of
The input terminal of the D conversion means is connected to the output terminal of the operational amplifier,
One end of the resistor is the output end of the detecting means, the other end of the third resistor and the fourth resistor are the positive input end of the operational amplifier, and the other end of the fourth resistor is D / A. The shake reduction device according to claim 1, wherein the shake reduction device is configured to be connected to an output end of the conversion means. 9. An optical device comprising the shake reduction device according to claim 1. 10. A camera comprising the shake reduction device according to claim 1.